Re: [PATCH 1/1] Fix: trace sched switch start/stop racy updates

[Valentin Schneider]

On 16/08/2019 21:57, Joel Fernandes wrote:
>> Can we finally put a foot down and tell compiler and standard committee
>> people to stop this insanity?
> 
> Sure, or could the compilers provide flags which prevent such optimization
> similar to -O* flags?
> 

How would you differentiate optimizations you want from those you don't with
just a flag? There's a reason we use volatile casts instead of declaring
everything volatile: we actually *want* those optimizations. It just so
happens that we don't want them *in some places*, and we have tools to tag
them as such.

The alternative is having a compiler that can magically correlate e.g. locked
writes with lock-free reads and properly handle them, but I don't think
there's a foolproof way of doing that.

> thanks,
> 
>  - Joel
>